Weird bug with Alembic & Blender 2.8 + Eevee
Here is the expression I use to loop and keep the stop motion effect :

(round(25*round(frame*wantedfps/globalframerate)/wantedfps) - 1) % animationlenght+ 1

It works in the viewport, or with Cycles and lightweight scenes in Eevee. But it doesn't work with my scene with Eevee until I unactiv some objects.